Yes. Unless you're Superman and can get just as hard as you were before, I would advise waiting until you're finished with your session. Some people even take it further and don't allow themselves an orgasm at all. There's some talk about how it could stall gains but I'm not so sure about the validity of those claims. I've also been reading more and more about
cockrings being beneficial during and after girth sessions so I finally bought some. I will post about the results if anyone cares to hear about it.